Originally Posted by
Gray Mole
Yeah, the highside is high, but not what I'd thought it would be.
I started at 100w to get a feel, and mainly had to add 134a and 290 to keep the HX flooding. -15 measured at the middle of the HX was the bare minimum. -20 seemed much better.
So 250w is all I could get. No matter how I played with it.
But 250w at -45c 8psi low/260psi high on a 1/2hp compressor is a start. Ethylene I think is just too much. In an autocascade I'd still be struggling with it at -20HX but it's working to a certain extent.
Cooldown is amazingly fast to -60 now, so that's where I do like how it's working, and the load temp for a 1/2hp is resonable. Just wish it had more capacity in it.
Which brings me back to Ethane.
I need the gasses to mix well, and not be a 'stepping stone' system. Finding enough to work a really long glide is going to be my best bet if it's going to be a system that works.
So I'll be reworking another SLHX at some point, maybe with 2 or 3 chambers to see if that actually does anything. I think it does assist the mix. Time will tell.
Ethane (I'm hoping) should be low enough pressure to do more. Lowest temp will be higher, but I need more of the lowtemp gas to condense. I'm getting there though, R23 never did a lot for me, and I feel that it's because of the weight of it.
Ethylene and Ethane are very light, and they tend to mix really well with most things, especially other hydrocarbons.
So I'll probably leave out the Ethylene on the next one, see if it works better without, then try a small addition and see if I can make the glide even longer, or if it's just out of reach.
Potentially a second SLHX but I don't see a benefit outside of an Auto. I just need to maintain a really cold slhx and with more 'room' to condense it may be more effective.
But that's where I'm at. HP is high, but still within a workable system.
So I'm happy enough with this project, until I get some Ethane to test next.
Gray
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